Semiconductor chips or dies typically are encapsulated in a package that protects the chips from the surrounding environment. The packages typically include leads or other connection points that allow the encapsulated die to be electrically coupled to another component, e.g., a printed circuit board. FIG. 1 is a schematic cross-sectional diagram of a microelectronic package 100 in accordance with the prior art. As shown in FIG. 1, the microelectronic package 100 includes a semiconductor die 104 attached directly to the leads 102 of a lead frame 101 with a die attach adhesive 105 in a leads-over-chip arrangement. Some or all of the terminals 106 of the semiconductor die 104 can be electrically connected to the leads 102 of the lead frame 101 by wire bonds 108. The connected lead frame 101 and die 104 may then be encapsulated in an encapsulant 110 to complete the microelectronic package 100.
The semiconductor die 104 typically generates a significant amount of heat that can cause structural and/or functional failure in the microelectronic package 100 if not adequately dissipated. In the leads-over-chip arrangement shown in FIG. 1, the die attach adhesive 105 typically provides an adequate thermal path to allow the leads 102 to conduct heat away from the semiconductor die 104. However, in other applications, the semiconductor die 104 may be attached to the leads 102 in a flip-chip arrangement with only solder balls or bumps (not shown), which may not provide an adequate thermal path to dissipate the generated heat from the semiconductor die 104. Accordingly, several improvements for enhancing heat dissipation in microelectronic packages may be desirable.